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[romprefix] Do not check for BBS compatibility
The existence and usage of the BEV entry point is covered by the PnP
spec, not the BBS spec; the BBS spec merely describes a policy for
selecting the boot device order.  iPXE should therefore check only for
a PnP BIOS in order to decide whether or not to hook INT19.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
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mcb30 committed Jun 24, 2010
1 parent 719b498 commit 3094d2c
Showing 1 changed file with 3 additions and 29 deletions.
32 changes: 3 additions & 29 deletions src/arch/i386/prefix/romprefix.S
Expand Up @@ -14,7 +14,6 @@ FILE_LICENCE ( GPL2_OR_LATER )
#define PMM_SIGNATURE ( '$' + ( 'P' << 8 ) + ( 'M' << 16 ) + ( 'M' << 24 ) )
#define PCI_SIGNATURE ( 'P' + ( 'C' << 8 ) + ( 'I' << 16 ) + ( ' ' << 24 ) )
#define STACK_MAGIC ( 'L' + ( 'R' << 8 ) + ( 'E' << 16 ) + ( 'T' << 24 ) )
#define PNP_GET_BBS_VERSION 0x60
#define PMM_ALLOCATE 0x0000
#define PMM_FIND 0x0001
#define PMM_HANDLE_BASE ( ( ( 'F' - 'A' + 1 ) << 26 ) + \
Expand Down Expand Up @@ -283,17 +282,8 @@ pnp_scan:
movw $init_message_pnp, %si
xorw %di, %di
call print_message
/* Check for BBS */
pushw %es:0x1b /* Real-mode data segment */
pushw %ds /* &(bbs_version) */
pushw $bbs_version
pushw $PNP_GET_BBS_VERSION
lcall *%es:0xd
addw $8, %sp
testw %ax, %ax
je got_bbs
no_pnp: /* Not PnP-compliant - therefore cannot be BBS-compliant */
no_bbs: /* Not BBS-compliant - must hook INT 19 */
jmp pnp_done
no_pnp: /* Not PnP-compliant - hook INT 19 */
movw $init_message_int19, %si
xorw %di, %di
call print_message
Expand All @@ -304,12 +294,7 @@ no_bbs: /* Not BBS-compliant - must hook INT 19 */
pushw %gs /* %gs contains runtime %cs */
pushw $int19_entry
popl %es:( 0x19 * 4 )
jmp bbs_done
got_bbs: /* BBS compliant - no need to hook INT 19 */
movw $init_message_bbs, %si
xorw %di, %di
call print_message
bbs_done:
pnp_done:

/* Check for PMM */
movw $( 0xe000 - 1 ), %bx
Expand Down Expand Up @@ -545,9 +530,6 @@ init_message_pci:
init_message_pnp:
.asciz " PnP"
.size init_message_pnp, . - init_message_pnp
init_message_bbs:
.asciz " BBS"
.size init_message_bbs, . - init_message_bbs
init_message_pmm:
.asciz " PMM"
.size init_message_pmm, . - init_message_pmm
Expand Down Expand Up @@ -617,14 +599,6 @@ decompress_to:
.long 0
.size decompress_to, . - decompress_to

/* BBS version
*
* Filled in by BBS BIOS. We ignore the value.
*/
bbs_version:
.word 0
.size bbs_version, . - bbs_version

/* Boot Execution Vector entry point
*
* Called by the PnP BIOS when it wants to boot us.
Expand Down

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